消化性溃疡最常见的并发症是
A．癌变B．出血C．急性穿孔D．幽门梗阻E．慢性穿孔
参考答案：B
The school sports meet, originally to be held last Sunday, was finally _________ because of the bad weather.
A．called off
B．worn off
C．set off
D．broken off
Windows的任务栏不可以_______。
A．和桌面图标一样删除
B．隐藏
C．改变大小
D．移动
